Stretching frame



June 3, 1941. F. c. OSBORN 2,244,473

STRETCHING FRAME Filed Sept. 14, 1939 2 Sheets-Sheet l n c E munln. 55v

' INVENTOR WITNESSES flank C- Osbowfi/ 7' ATTORl3 EY5 2 sheets-Sheet 2 INVENTOR Fran C- Osbor'w l E ATTORNEYS DTNESSES 1 Patented June 3, 1941 UNITED STATES PATENT FFICE 2,244,473 STRETCHING FRAME Frank C. Osborn, Manchester, Vt.

Application September 14, 1939, Serial No. 294,850

Claims.

This invention relates to stretching frames, and more particularly canvas stretching frames, although it is adaptable to picture frames and to any other uses where there is a necessity of stretching sheet material whether of cloth, paper or other fabric. we will refer in this specification to stretching canvas since this is one of the uses to which my invention is most readily adaptable.

An object of the invention is to provide a stretcher in which canvas or other material may be simply and quickly stretched without permanently fastening the canvas in the frame.

Another object is to provide a stretching frame in which canvas may be placed and removed at will and in which the degree of tension placed upon the canvas may be simply and readily controlled. A great many materials, such as canvas, react to atmospheric conditions and it is essential that the tension thereon may be varied at will.

A further object is to provide a device of the character described which will be compact in form and adaptable to a number of canvases.

With these and other objects in view reference is had to the accompanying drawings, in which- Fig. 1 shows a plan view of a canvas stretcher embodying my invention;

Fig. 2 is a sectional view taken on the line 2--2 of Fig. 1;

Fig. 3 is a sectional view taken on the line 3--3 of Fig. 1;

Fig. 4 is a sectional view taken on the line 4-4 of Fig. 1;

Fig. 5 is a cross-sectional view taken on the line 55 of Fig. 1;

Fig. 6 is a cross-sectional view taken on the line fi6 of Fig. 1;

. Fig. 7 is a cross-sectional view taken on the line 1-! of Fig. 1;

Fig. 8 is a plan view in section of a modified form of my invention;

Fig. 9 is a cross-sectional view taken on the line 9-9 of Fig. 8.

I provide an outer frame I5, preferably made of metal such as Monel metal or steel, which would be light but strong in construction and which is best formed at an angle as shown in Fig. 3. An inner frame 56 is fastened to one end of the outer frame by the hinge ll. While I have shown my inner frame as made of U-shaped metal, it will be appreciated that this may be made of wood or any suitable material. The inner frame l6 fits within the outer frame l5.

On the outer frame l5 are a series of pins l8 For the purpose of simplicity adapted to register with holes [9 on the inner frame IS. The pins It may be welded to the outer frame I5, or as shown in Fig. 9, may be integral therewith. In order to hold the frame l6 within the frame iii a latch 2i! with a tongue 2! is pivoted at 22 to the frame it. This latch 20 engages openings 23 in the frame l5 and 24 in the frame E6 to hold the frames in a closed position.

Mounted in the frame it are a plurality of guide members 30 in which are mounted sliding members 3!. On the sliding members 3| are a plurality of earns 32 mounted at an angle to the longitudinal axis of the sliding members 3|. On each of the sliding members 3| is mounted a handle 35. The handle 35 has an elongated slot 36 engaging a pin 3'! on the member 3i. The lower portion of the handle 35 has a rounded shoulder 25 and the edge 26 of the handle member 35 adjacent the rounded shoulder 25 contacts a wall 21. It will be apparent that when the handle 35 is moved outwardly to the full extent of the slot 36, the handle 35 may be folded into the frame due to the fact that the rounded shoulder 25 will pass the wall 21. However, when the handle 35 is moved inwardly, the edge 26 thereof engages the wall 2! and prevents the lowering or folding of the handle 35. It will thus be seen that when the handle is pushed inwardly, as shown in Fig. 4, the slide members 3! may be moved in either direction, but when the handle 35 is pulled directlyaway from the frame it may be pivoted downwardly out of the way, as shown in Fig. 7. The end 38 of the handle 35 engages a spring 39 on the sliding member 31 when the handle is out of use to prevent its Talling outwardly.

I also provide a stretching frame 46 normally made of wood or some similar material. Mounted on the stretching frame 40 are a plurality of studs 4| placed on the stretching frame 40 by means of the plate 42 or by any other suitable means. The forward edge of the stretching frame 40 is beveled to form a shoulder at 43 to form a contact surface for stretching purposes, and the studs 4! are adapted to engage the inclined cam 32 so that when the sliding member 3| is pulled in one direction the cams 32 will exert pressure upon the studs 4| thus forcing the stretching frame 40 toward the front of the outer frame I5.

I have also provided springs 45 on the stretching frame 40 which are slidably held by screws 46 to the loop ends 41 of the springs 45. The springs 45 engage a screw 49 in the inner portion of the frame It and tend to hold the stretching frame 49 rearwardly, that is, toward the rear of the frame It, and to position the frame so within the frame l6 when the frame It is moved out of the outer frame l5. Thus it will be seen that the hinged unit formed by the frames l and i6 may be opened and the frame 16 bearing the stretching frame 49 moved on the hinge ii.

My invention avoids the necessity of hand stretching and fastening the canvas on a stretching frame similar to the frame d3 while the canvas is being painted, and makes it possible to stretch canvases for painting purposes and to remove them and substitute others before the painting is finished, if desired. Obviously the finished painting would be i e-stretched on a permanent frame but my invention makes it unnecessary for the painter to perform this Work until the canvas is finished. that the painting surface of the canvas 50 is within the shoulder Q3 of the frame 40 and that when the canvas is finished an unpainted portion of just the right dimensions is reserved for final stretching of the canvas on a regular stretcher frame with a slight excess to allow the use of canvas pliers.

In the operation of my invention the frame iii is swung on the hinge If! upwardly and away from the outer frame 15. by opening the latches 20 and separating the frames. A canvas 50 is then placed in the outer frame it upon the pins [8. The frame it is then swung into place forcing the pins it through the canvas and the latches 2f] swung into place to hold the frames l5 and it together. By swinging the handles upwardly and dropping them so that -the edge 26 thereof contacts the wall 2?, the slide members 3| may be moved to increase the pressure of the inclined cam 32 against the studs M on the stretching frame 60. This forces the shoulder 43 against the canvas Ed at 5! and exerts an even pressure throughout the entire canvas. If it is desired to substitute another canvas, pressure is released by moving the handles 35 in the opposite direction opening the frame and removing the canvas 59 from the pins l8.

In the modified form of my invention shown in Figs. 8 and 9, a segmental quadrant 6!! having teeth 8! is mounted at E2 on the stretching frame A slide member 63 has a section with teeth 6 which engage the teeth Bl. The slide member 63 has cam surfaces 65 which cam surfaces engage studs 85 mounted on the inner frame it. The preliminary operation of the modified form is the same as that heretofore described, and the slide member 83 is moved by the operation of a handle 67 thus varying the pressure exerted by the cam surfaces 85 on the studs 66. In order to prevent the movement of the frame so within the frame l6, screws in are provided which engage projections H in a portion of the frame it to position the frame MI within the frame it and to prevent its movement when the It will be noted i This is done merely pressure is changed. A strip of cardboard matting ?2 or similar soft material may be placed on the pins I8 before placing the canvas thereon. While not necessary, this strip insures a better grip upon the canvas.

I claim:

1. In a device of the character described, an outer frame member, an inner frame member hinged thereto and adapted to rest within said outer frame member, means on said inner and outer frame members to position material to be stretched, a stretching frame mounted within said inner and outer frame members, studs on said stretching frame, members having cam surfaces slidably mounted on said inner frame member and engaging said studs, and means for moving said cam bearing members in and out of selective positions.

2. A- device of the character described including an outer frame assembly, means for positioning material to be stretched in said outer frame assembly, a stretching frame positioned insaid outer frame assembly, and means for forcing said stretching frame forwardly against the material to be stretched, said means including members having cam surfaces mounted on one of said frames, studs engaging said cam surfaces on the other of said frames, and means for moving said members bearing the cam surfaces With relation to the studs.

3. A device of the character described including an outer frame assembly, means for positioning material to be stretched in said outer frame assembly, a stretching frame positioned in said outer frame assembly, and means for forcing said stretching frame forwardly against the material to be stretched, said means including studs mounted on one of said frames and sliding cam surfaces engaging said studs, on the other of said frames.

l. A device of the character described comprising an outer frame, an inner frame hinged thereto at one end thereof, means for maintaining said frames in a closed position, additional means for positioning material :to be stretched between said frames, a stretching frame resiliently mounted within said inner frame, means for forcing said stretching frame forwardly against the material to be stretched, said means including studs and slidable cam surfaces, and additional means for positioning said cam surfaces with relation to said studs.

5. A device of the character described comprising an outer frame, an inner frame hinged thereto at one end thereof, means for positioning material to be stretched between said frames, a stretching frame resiliently mounted within said inner frame, means for forcing said stretching frame forwardly against the material to be stretched, said means including studs and slidable cam surfaces, and operating handles to position said cam surfaces with relation to said studs.

FRANK C. OSBORN. 

